NEW YORK, NY, USA - No.9 seed Johanna Konta was forced to work hard by compatriot Heather Watson in an all-British first-round derby at the US Open, saving six set points in the first set before pulling away 7-6(7), 6-1 in one hour and 47 minutes.

"I think whenever you play a compatriot there is an extra level of anxiety and stress for a number of different reasons," Konta admitted after the match. "I think I was kind of anticipating that, expecting that. I just kind of wanted to put that to one side and enjoy playing a really good player, competing well.

"I was pleased with how I competed and kind of just asked that question from my opponent today of, for her to also keep raising her level the whole match."

British No.1 Konta had never lost to British No.2 Watson in three prior encounters, nor indeed to any fellow countrywoman in five previous domestic derbies at WTA level, but needed to draw on all of her clutch serving prowess to progress today, firing 11 aces, 27 winners to 19 unforced errors and winning 80% of her first serve points.

"Obviously, there is more interest at home, so there will be more opinions from people at home. Obviously we spend a lot of time together. There's always going to be rivalry between compatriots. It's always going to be that extra stressful."

A knife-edge first set was dominated by the serve - perhaps surprisingly, in the opening stages, particularly by Watson's. The World No.54, who had collected her fourth career title in Acapulco this February just before the Tour shutdown, slammed down seven aces in her first four service games, eventually tallying eight for the set and 12 for the day.

Nonetheless, it was Konta who had more chances earlier on. The Cincinnati semifinalist was unable to take a break point in the third game, and came out on the wrong end of a 10-minute, seven-deuce marathon seventh after Watson staved off another two break points.

Shaking off these lost opportunities, Konta unleashed her forehand with renewed ferocity to capture the younger Briton's delivery for a 5-4 lead - only for Watson, who had only won four points on Konta's serve to this point, to take advantage of the former World No.4's errant backhand to immediately break back.

Now, it was Watson attempting to press ahead to an increasingly important first-set lead - but Konta, with her back to the wall, raining down service bullets. Down double set point at 5-6, the three-time Grand Slam semifinalist found a service winner before Watson netted a backhand. In a tiebreak that saw 10 unreturned serves out of 16 points, Konta escaped four more set points, including three in a row down 3-6, thanks to a sixth ace, two service winners and - on Watson's serve - a bold net-rush that elicited another backhand error from her opponent.

By contrast, the 29-year-old needed only one set point of her own, snatching the coveted lead after 71 minutes as Watson sent a forehand wide.

Unsurprisingly after such an epic first stanza, Konta was able to sustain her momentum to forge ahead in the second set. Three aces in the opening game were a significant statement of her intent to keep her foot on the gas; Watson, however, was beginning to falter, coughing up two double faults to bring up an immediate break opportunity for Konta. A netted slice from the former World No.38 sealed it, and matters only continued to unravel from there.

A fourth double fault got her in trouble again in the fourth game of the set, and Konta would convert this chance by lofting a perfect lob over Watson's head before a love hold moved her up 5-0. Watson managed to avoid the dreaded bagel set after Konta netted a backhand putaway on her first match point, but there was no escaping the ferocity of the 2019 US Open quarterfinalist's serve, and another love hold sealed a second-round date against Sorana Cirstea.

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